If Statement

Each part of the if statement must be a single statement.
If we want to execute more than one statement then we must combine them into a single block statement using curly brackets.
In C# the parentheses around the condition to be tested is compulsory.

If

if (bValue == true) 
{ 
   sVariable1 = "text"; 
} 

'VB.Net Equivalent
If (bValue = True) Then 
   sVariable1 = "text"; 
End If 

You can put everything on one line, but this makes it much harder to read.

if (bValue == true) sVariable1 = "text"; 

'VB.Net Equivalent
If (bValue = True) Then sVariable1 = "text"; 
If (bValue = True) Then _ 
   sVariable1 = "text"; 

If - Else

if (bValue == true) 
{ 
   sVariable1 = "text"; 
} 
else 
{ 
   sVariable2 = "text"; 
} 

'VB.Net Equivalent
If (bValue = True) Then 
   sVariable1 = "text"; 
Else 
   sVariable2 = "text"; 
End If 

You can leave out the curly brackets when there is only one statement to execute.
This makes it much harder to read and means you are limited to just one statement.

if (bValue == true) 
   sVariable1 = "text"; 
else 
   sVariable2 = "text"; 

You can use the Tenary Operator

if (bValue == true) ? sVariable1 = "text" sVariable2 = "text"; 

If - ElseIf - Else

Very important to remember that "else if" is 2 words in C# but "ElseIf" is 1 word in VB.Net.

if (iValue < 10) 
{ 
} 
else if (iValue < 20) 
{ 
} 
else 
{ 
} 

'VB.Net Equivalent
If (iValue < 10) Then 

ElseIf (iValue < 20) 

Else 

End If 

If (OR)

if ( ( a > b ) | ( c < d ) ) 
{ 
} 

'VB.Net Equivalent
If ( a > b ) Or ( c < d ) Then 
End If 

If (OR conditional)

You can use the "OrElse" if you do not want the second expression evaluated when the first expression is not true

if ( ( a > b ) || ( c < d ) ) 
{ 
} 

'VB.Net Equivalent
If ( a > b ) OrElse ( c < d ) Then 
End If 

If (AND)

if ( ( a > b ) & ( c < d ) ) 
{ 
} 

'VB.Net Equivalent
If ( a > b ) And ( c < d ) Then 
End If 

If (AND conditional)

You can use the "OrElse" if you do not want the second expression evaluated when the first expression is not true

if ( ( a > b ) && ( c < d ) ) 
{ 
} 

'VB.Net Equivalent
If ( a > b ) AndElse ( c < d ) Then 
End If 

If Nested

if (bValue === false) 
{ 
   if (iValue < 10) 
   { 
   } 
} 

'VB.Net Equivalent
If (bValue = False) Then 
   If (iValue < 10) Then 
   End If 
End If 

Immediate IF

bool breturn; 
breturn = (inumber<10 ? svariable1="some" : svariable2="text") 
breturn = (expression ? True action : False action) 

Dim breturn As Boolean 
breturn = If(inumber<10, svariable1="some", svariable2="text") 
breturn = If(expression, True action, False action)